Structure for protecting a suction cleaner motor from overheating



Feb. 1, 1966 o. s. OWENMARK 3,232,030

STRUCTURE FOR PROTECTING A SUCTION CLEANER MOTOR FROM OVERHEATING Original Filed Feb. 5, 1962 3 Sheets-Sheet l IN VENTOR.

Feb. 1, 1966 o s. OWENMARK 3,232,030

STRUCTURE FOR PROTECTING A SUCTION CLEANER MOTOR FROM OVERHEATING Original Filed Feb. 5, 1962 3 Sheets-Sheet 2 a INVENTOR.

hirrolr/nfr Feb. 1, 1966 o. s. OWENMARK 3,232,030

STRUCTURE FOR PROTECTING A SUCTION CLEANER MOTOR FROM OVERHEATING Griginal Filed Feb. 5, 1962 3 Sheets-Sheet 5 FIG 5 IN VENTOR.

EX M WM M United States Patent "ice 3 232 930 a STRUCTURE non fiRoiECTING A SUCTION (ILEANER Moron FnoM ovnnnnarnso Olov-Stanley Owenmarlt, Etockholm, Sweden, assignor to htiebolagct Electrolux, Stockholm, Sweden, a corporation of Sweden 7 Continuation of application Ser. No. 171,167, Feb. 5, 1962. This application July 23,1965, Ser. No. 474,446

Claims priority, application Sweden, Feb. 4, 1961,

1,172/61 Q 8 Claims. (Cl. 55-217) This application, which is a continuation of appli{ cation Serial No. 171,167, filed February 5, 1962, relates to suction cleaners of the type in which air circulated by a motor-fan unit flows through a removable dust bag or filter element to remove, and collect dust entrained in the air, and it is an object toprovide an improvement for protecting the motor in this type :of suction cleaner from overheating. 1 p t More particularly, it is an objectto provide a thermal device for protecting the suction cleaner motor whenever it reaches an abnormally high temperature.

Further objects and advantages of my invention will become apparent as the following description proceeds,

and the features of novelty which characterize the inven- 3,232,030 Patented Feb. 1, 1966 cooperates with the dirt-collecting bag 25 at its open end to provide an air-tight seal therebetween.

The cover 26 is formed with an inlet 29 to which a suction hose (not shown) is adapted to be removably connected. Suitable cleaning tools may be connected to a wand which in turn is connected to the outer free end of the suction hose and through which air flows through the inlet 29 by motor-fan units 30 disposed in the righthand part of the casing 10. The motor-fan units 30 are connected in parallel in an electrical circuit having a switch (not shown) provided with a manually operable control member 31 at the side wall 12 of the casing 10. Dirt entrained in air drawn into the inlet 29 is separated from the air when it passes through the dirt-collecting bag 25, and air from which dirt has been removed flows from space 20 through an opening 32 in the bottom vertical partition section 17b into the bottom horizontal space 21.

Each motor-fan unit 30 includes a centrifugal fan 33 carried at the lower end of an'electricmotor 34. The horizontal partition 18 is formed with a pair of openings in which the motor-fan units 30 are resiliently mounted at 35, as best shown in FIG. 2. The motor-fan units 30 are mounted on the partition 18 in such a manner that the fans 33 are disposed in the bottom space 21 and the motors 34 are disposed in the space 22 between the horizontal partitions 18 and 19. Air free of dirt and flowing into the bottom horizontal space 21 passes into the inlets 36 of the fans 33 which are positioned alongside one another. All of the air discharged from the fans 33 flows through the motors 34 to elfect cooling thereof,

such air passing from the motors at 37 and flowing from FIG. is a diagrammatic illustration of another em bodiment of the invention;

1 FIG. 6 is an enlarged fragmentary topview of a part of the suction cleaner shown in FIG. 1, partly broken away, to illustrate details more clearly; and

FIG. 7 is a fragmentary sectional view taken 'at line 7-7 of FIG. 6. 1

Referring to FIGS. 1 and 2, the suction cleaner which I have shown embodying the invention comprises an elongated casing having a bottom: 11 and an upstanding side wall 12. The casing 10 is provided with a handle 14 and with wheels and '16 to facilitate movement thereof on a supporting surface, the wheels 15 being at opposite sides of thecasing and the single caster wheel 16 at the front end of the casing being disposed between the side walls of the cleaner in a recessed part in the bot tom 11.

The casing is provided with a vertical partition 17 and horizontal partitions 18 and 19 to divide the casing into a vertically extending space and horizontally extending spaces 21, 22 and 23. Thevertical space 20, which the horizontal space 22 through a hollow sleeve section 38 extending downwardfrom an opening 39 in the horiaontal partition 19. r

The air passes from the hollow sleeve section 38 into adifruser 40 which is formed of porous material and includes a neck portion 41 which is resiliently held (not shown) by a wire frame 42 against the top of the partition 19 in air-tight sealing relation therewith about the opening 39. The air discharged from the electric mo-.

be hinged to the casing 10 (not shown) at the vicinity of the pivotal connection 27 for the cover 26 and held in its normal position by a latch having an operating memis defined by the left-hand part of casinglil and the top and bottom sections 17a and 17b of the vertical partition 17, is provided with an apertured top 24 which forms a part of the casing 10 andis adapted to receive an air permeable dirt-collecting bag 25. The dirt-collecting bag 25 is provided with a gasket 25a at the top open end thereof which is supported about the opening 244 in the top 24 and anchored in place in any suitable mannen as by a downwardly depending flange 26a at the underside of a cover 26, as shown inFIG. 7. The cover 26 is pivotally mounted on the casing at 27 and held in its closed position by a movable latch 28. It will be understood that in its closed position the flange 26a of the cover 26 her 45 at an end of the casing It The tray or basket 43 may be employed for storing cleaning tools, such as nozzles and the like, when they are not being used for cleaning.

During normal circulation of air through the suction cleaner the motors 34 are effectively cooled by the air flowing therethrough and operates in a normal temperature range. However, the inner surface of the dirt-collecting bag 25 can eventually become so clogged with dirt that circulation of air through the suction cleaner wiil be insufficient to cool the motors 34 and objectionable overheating willtake place.

In accordance with my invention, in order to protect motors 34 from overheating I provide a thermaily opcrease, respectively, in temp rature. The expansible fluid thermostat 46 includes a tiermal element or bulb 47 which is mounted by a spring clip 43 in the horizontal space 22 in which the meters 34 are disposed. The bulb 47 is connected to one end of a tubular member 49 forming a component of the thermostat which passes through an aperture formed in the horizontal partition E8, the opposite end of the tubular member being connected to the upper end of an expansible bellows 50 forming another component of the thermostat. The upper end of the bellows 50 is secured to an arm 51 of a bracket 52 which is parallel to and between the bracket end arms 53 and S4. The bracket 52 is mounted at the bottom of horizontal partition 18 by an angle member 55.

The lower end of the bellows 59 is fixed to the downwardly extending arms 55 of a stirrup having its upper closed end 57 secured to the lower end of a rod 58 vertically movable through an opening in the upper arm 53 of bracket 52. A spring is provided between the lower arm 54 of bracket 52 and the bottom of the bellows 50 to bias the bottom movable end of the bellows toward the upper stationary end of the bellows.

The upper end of the rod 58 extends through an opening in a flange of support 69 fixed to the underside of the aperturecl top 24 of the casing 18. The apertured top 24-, at a region or space 20 which is exterior of the dirt-collecting bag 25 and at a peripheral edge portion of the top 24 disposed about the opening 24:: therein, is provided with an opening 61 which is covered by an apertured member 62, as best shown in FIG. 6. The opening 61 in the top as is adapted to be closed by a valve 63 fixed to the upper end of the rod 58 which may be referred to as a valve spindle. The valve 63 is urged upward to its closed position by a helical spring 64 disposed about the rod 58 between the flange of the support 60 and the underside of the valve 63. The valve 63 in its open position establishes communication between the atmosphere and the vertical space 20 through the passage or opening 61 when the cover 26 is in its closed position and the flange Eda thereof is in air-tight sealing relation with the upper open end of the dirt-collecting bag 25. This is so because the opening 62 is located at a region of the apertured top 24 which is adjacent to one of its corners and outside the zone at which the dirt-collecting bag 25 depends downward from the cover 26.

As explained above, the top 24'; forms a part of the casing and the cover 26 simply overlies the top 24 when it is in its closed position, as best shown in FIGS. 1 and 6. In the closed position of the cover 26 only that part thereof within the circular flange 26a is sealed oi? from the surrounding atmosphere and atmospheric air can pass to the underside of the cover 26 at the vicinity of the hinge 27, as indicated by the arrows in FIGS. 6 and 7. Hence, when valve 63 is in its open position, atmospheric air at the underside of the cover 26 about the flange 26a can pass through the opening 61 and be drawn into the space by the suction action of the motor-fan units 30.

During normal operation of the suction cleaner, when dust-laden air is drawn into the casino through the first inlet 29 and air free of dust passes through the dirt-collecting bag and the motors 34 are being cooled by air circulating therethrough and in a normal temperature range, the thermal bulb i7 is affected by the temperature condition of the motors and the temperature of the air discharged from the motors, and the volatile fluid in the expansible fluid thermostat is of such volume that the spring 5) efiectively moves the lower movable end of the bellows 50 upward and imparts upward movement to the stirrup and rod 58 to move valve 63 to its closed position and shut the opening or second air inlet 61 for the cleaner, such upward movement of the rod being aided by the upward biasing action of the spring 6 In the event the dirt-collecting bag 25 becomes so clogged with dust that circulation of air through the suction cleaner will be sufficieut to cool the motors 34, objectionable overheating will take place. Under these conditions the thermal bulb 47 is afi'ec ed by the temperature condition of the motors and the volatile fluid in the xpansible fluid thermostat 46 increases in volume. This causes the bellows to expand against the upward biasing action of the springs 59 and 6 2-, thereby moving the lower movable end of the bellows 5t) downward and imparting downward movement to the stirrup and rod 53 to move the valve 63 to its open position.

With valve 63 open, the normal operation of the suction cleaner is altered or interrupted and air from the atmosphere is drawn into space 20 through the second air inlet or passage of by the motor-fan units. Such air, which is drawn into that part of space 20 which surrounds the dirt-collecting bag 2 and accordingly by-passes it, flows to the inlets st, of the fans 33 and is discharged therefrom for how through the motors 34 for effectively cooling them.

By locating the valve 63 in the casing 10 in such manner that it can be readily observed when it moves to its open position, anyone in the vicinity of the cleaner will immediately know the dirt-collecting bag 25 should be removed to be cleaned or replaced by a fresh dirt-collecting bag. In View of the foregoing, it will now be understood that the valve 63, rod 58, stirrup connected to the lower end of the rod and other parts associated therewith like the support 60, spring 64 and bracket 52 constitute mechanism for moving valve 63 to its open position by thermal means comprising the expansible fluid thermostat 46. The valve 63 of the device normally is Closed and stops flow of air through the opening or second air inlet 61 and is actuated to its open position to instigate flow of air through the opening to the fan 33.

In FIG. 5, I have shown another embodiment of the invention which is similar to the embodiment of FIG. 3 and also includes an indicator 70. In FIG. 5, in which parts similar to those illustrated in the first-described embodiment are referred to by the same reference numerals, each motor 34 includes an armature 34a and a field winding 34b connected in series therewith and to which current is supplied from a source of electrical supply through conductors 65a and 66a. A manually operable switch 67 is connected in conductor 65a for starting and stopping the suction cleaner. The indicator 70 is connected in a normally open branch circuit associated with conductors 65a and 66a to which the motors 34 are connected. The branch circuit comprises conductors 65b and 66b in which is connected an electric light bulb serving as the indicator 70. A normally open switch 71 is connected in the branch circuit, such switch having a pair of contacts 71a adapted to be closed by a contact bar 71b which is fixed to the rod 581; and may be formed of insulating material.

The operation of the embodiment of FIG. 5 is similar to that of the first described embodiment illustrated in FIG. 3, as explained above. In addition, when objectionable overheating of the motors 34 takes place and rod 58b moves downward to move valve 63 to its open position, the contact bar 71b also will move downward to bridge the contacts 710 and complete an electrical circuit for the indicator 70. This will immediately indicate to anyone in the vicinity of the suction cleaner that the dirtcollecting ba g 25 should be cleaned or replaced by a fresh dirt-collecting bag.

In my improved suction cleaner the casing 19 is provided with first and second air inlets 28 and 6!, respectively, and an outlet at the sides of the open-top tray or basket 43. The opening 32 in the partition section 17b constitutes a zone from which a first pasageway extends through the interior of the dust collector 25 to the first air inlet 25 and from which a second passageway extends through the space 2%) to the second air inlet 61. A common passageway extends from the zone 32 to the air outlet about the sides of the tray 43 which includes the spaces arm 56 of the stirrup and bellows 50 constitue mechanism for moving the valve 63 from its closed position to its open position against the action of the resilient biasing means formed by the spring 64. The mechanism just described is inoperable to movethe valve 63 from its closed position to its open position when the motors 34 operate in a normal temperaturerange and the :air permeable dirt collect-or normally functions to allow air to flow therethrough during operation of the cleaner.

As explained above, the motors 34 tend to operate at an abnormally high temperature above the normal temperature range when sufiicient dirt collects in the air permeable dirt collector to obstruct flow of air thercthrough, whereby normal cooling of the motors 34 is impaired.

The fluidcperated thermostat 46 is responsive to .a term perature condition affected by the motors 34 when the latter operate at the abnormally high temperature to render the mechanism describe/cl above operable to move the valve as from its closed position against the action of the biasing means 64 While the switch 67 is in its closed position and the motors 34 are connected to the source of electrical energy. Under these conditions, the valve 63 moves to its open position and functions to allow air to flow successively through the second passageway 20 and the common passageway to promote cooling of the motors 34 by air flowing therethrough, whereby the motors 34 will operate again in the normal temperature range.

Although I have shown and described several embodiments of my invention, I do not wish to be limited to the particular arrangements .set forth, and I intend in the following claims to cover all modifications which do not depart from the spirit and scope of my invention.

I claim: 1. A suction cleaner comprising a casing, said casing having first and second inlets for air and an outlet for air, said casing from a zone intermediate said outlet and said first and second inlets having first and second passageways extending therefrom which respectively communicate with said first and second inlets and a common passageway extending from said zone which communicates with said first and second passageways and said outlet, means in said common passageway for flowing air through said first and second passageways and thence through said common passageway from said first and second inlets to said outlet, an air permeable dirt collector in said first passageway tor collecting dirt from air which passes therethrough, i valve means movable between open and closed positions for controlling iiow of air through said second passageway, means for normally closed position, said air moving means including an electric motor and a fan driven thereby, means including a manually operable switch movable between closed and open positions for respectively connecting and disconnecting said motor to and from a source of electrical energy, said fan being connected to receive air from said first and second passageways, means to flow all of the air discharged from said fan through said motor to effect cooling thereof, mechanism for moving said valve means from its closed position to its open position against the action of said biasing means,

biasing said valve means to its said mechanism normally being inoperable to move said valve means from its closed position to its open position when said motor operates in a normal temperature range and said air permeable dirt collector normally functions to allow air to flow thercthrough during operation of the cleaner, said motor tending to operate at an abnormally high temperature above said normal temperature range when sufficient dirt collects in said air permeable dirt collector to obstruct flow of air therethrough, whereby normal cooling of said motor is impaired, and means responsive to a temperature condition aficcted by said motor when the latter operates at said abnormally high temperature to render said mechanism operable to move said valve means from its closed position to its open position against the action of said biasing means while said switch is in its closed position and said motor is connected to the source of electrical energy, said valve means in its open position functioning to allow air to fiowsuccessively through said second passageway and said common passageway to promote cooling of said motor by air flowing therethrough, whereby said motor will operate again in said normal temperature range. 2. Apparatus as set forth in claim 1 in which said electric motor forms part of an electric circuit which iricludes a branch having a normally open switch, an electrical indicator connected in said branch, and said means responsive to a temperature condition affected by said motor when the latter operates at an abnormally high temperature also being operable to close said last-mentioned normally open switch and energize said indicator.

3. Apparatus as set forth in claim 2 in which said indicator comprises an electric light bulb.

4. A suction cleaner comprising a casing having first and second inlets for air and a single outlet for air, said casing having first and second passageways respectively communicating with the first and second air inlets and a common air passageway communicating with the single air outlet, a plurality of air moving means for ciruclating air through said casing from said first and second air inlets to said single air outlet, a dirt collector in said first passageway between said first inlet and all of said air moving means for removing dirt from air which passes therethrough, a device for controlling flow of air through said second passageway from said second air inlet to all of said air moving means, said device comprising a part movable between first and second positions and normally remaining in its second position to stop flow of air through saidsecond passageway from said second air inlet to all of said air moving means, means for actuating said device to move said part to its first position to instigate flow of air through said second passageway from said second air inlet to all of said air moving means, each of said air moving means including an electric motor and a fan driven thereby, means including a manually operable switch movable between closed and open positions for respectively connecting and disconnecting all of said motors to and from a source of electrcial energy substantially at the same time, each of said fans being connected circulation of air through said first passageway from said first inlet to all of said fans through said dirt collector, and means responsive to a temperature condition affected by said motors Whenever said dirt collector becomes suf- ,ficiently clogged to reduce flow of air through said first passageway and at least one of said motors reaches a temperature higher than that attained in said normal range to actuate said device to move it to its first position to instigate flow of air through said second passageway from said second inlet to all of said fans while said switch is in its closed position and said motors are connected to the source of electrical energy and operable to drive all of said fans, whereby the temperature of at least said one motor will be reduced to a value at least as low as that attained in said normal temperature range.

5. Apparatus as set forth in claim 4 in which said casing has an opening communicating with the atmosphere and a passageway having one end in communication with the opening and the opposite end in communication with the inlets of all of said fans, said last-mentioned passageway by-passing said dirt collector and defining said second air passageway, said device comprising valve means movable between a closed position at which it normally remains to close said second passageway and an open position to open said second passageway, said means operable to actuate said device functioning to move said valve means from its normal closed position to its open position to open said second passageway whenever at least one of said motors reaches the higher temperature, said means operable to actuate said device comprising a thermostat containing a fluid which increases and decreases in volume responsive to increase and decrease, respectively, in temperature, said thermostat including an element responsive to the temperature condition affected by at least one of said motors and a part having a flexible wall portion and tubing connecting said element and said part, said part coacting with said valve means and functioning to move the latter from its closed position to its open position whenever at least one of said motors reaches the higher temperature.

6. Apparatus as set forth in claim 5 in which said part comprises an expansible bellows.

7. Apparatus as set forth in claim 6 in which said casing includes a partition, said partition being apertured for said tubing to pass therethrongh, and said element being disposed at one side of said partition and said expansible bellows being disposed at the opposite side of said partition.

8. Apparatus as set forth in claim 7 in which said valve means includes a spindle, and bracket means for mounting said bellows on said partition, said valve spindle being connected to said bellows.

References (Iited by the Examiner UNITED STATES PATENTS 2,625,239 1/1953 Senne 55217 2,715,452 8/1955 Kent 55-217 3,031,824- 5/1962 Court 55-217 3,180,071 4/ 1965 Nolte 55213 ROBERT F. EURNETT, Primary Examiner. 

1. A SUCTION CLEANER COMPRISING A CASING, SAID CASING HAVING FIRST AND SECOND INLETS FOR AIR AND AN OUTLET FOR AIR, SAID CASING FROM A ZONE INTERMEDIATE SAID OUTLET AND SAID FIRST AND SECOND INLETS HAVING FIRST AND SECOND PASSAGEWAYS EXTENDING THEREFROM WHICH RESPECTIVELY COMMUNICATE WITH SAID FIRST AND SECOND INLETS AND A COMMON PASSAGEWAY EXTENDING FROM SAID ZONE WHICH COMMUNICATES WITH SAID FIRST AND SECOND PASSAGEWAYS AND SAID OUTLET, MEANS IN SAID COMMON PASSAGEWAY FOR FLOWING AIR THROUGH SAID FIRST AND SECOND PASSAGEWAYS AND THENCE THROUGH SAID COMMON PASSAGEWAY FROM SAID FIRST AND SECOND INLETS TO SAID OUTLET, AN AIR PERMEABLE DIRT COLLECTOR IN SAID FIRST PASSAGEWAY FOR COLLECTING DIRT FROM AIR WHICH PASSED THERETHROUGH, VALVE MEANS MOVABLE BETWEEN OPEN AND CLOSED POSITIONS FOR CONTROLLING FLOW OF AIR THROUGH SAID SECOND PASSAGEWAY, MEANS FOR NORMALLY BIASING SAID VALVE MEANS TO ITS CLOSED POSITION, SAID AIR MOVING MEANS INCLUDING AN ELECTRIC MOTOR AND A FAN DRIVEN THEREBY, MEANS INCLUDING A MANUALLY OPERABLE SWITCH MOVABLY BETWEEN CLOSED AND OPEN POSITIONS FOR RESPECTIVELY CONNECTING AND DISCONNECTING SAID MOTOR TO AND FROM A SOURCE OF ELECTRICAL ENERGY, SAID FAN BEING CONNECTED TO RECEIVE AIR FROM SAID FIRST AND SECOND PASSAGEWAYS, MEANS TO FLOW ALL OF THE AIR DISCHARGED FROM SAID FAN THROUGH SAID MOTOR TO EFFECT COOLING THEREOF, MECHANISM FOR MOVING SAID VALVE MEANS FROM ITS CLOSED POSITION TO ITS OPEN POSITION AGAINST THE ACTION OF SAID BIASING MEANS, SAID MECHANISM NORMALLY BEING INOPERABLE TO MOVE SAID VALVE MEANS FROM ITS CLOSED POSITION TO ITS OPEN POSITION WHEN SAID MOTOR OPERATES IN A NORMAL TEMPERATURE RANGE AND SAID AIR PERMEABLE DIRT COLLECTOR NORMALLY FUNCTIONS TO ALLOW AIR TO FLOW THERETHROUGH DURING OPERATION OF THE CLEANER, SAID MOTOR TENDING TO OPERATE AT AN ABNORMALLY HIGH TEMPERATURE ABOVE SAID NORMAL TEMPERATURE RANGE WHEN SUFFICIENT DIRT COLLECTS IN SAID AIR PERMEABLE DIRT COLLECTOR TO OBSTRUCT FLOW OF AIR THERETHROUGH, WHEREBY NORMAL COOLING OF SAID MOTOR IS IMPAIRED, AND MEANS RESPONSIVE TO A TEMPERATURE CONDITION AFFECTED BY SAID MOTOR WHEN THE LATTER OPERATES AT SAID ABNORMALLY HIGH TEMPERATURE TO RENDER SAID MECHANISM OPERABLE TO MOVE SAID VALVE MEANS FROM ITS CLOSED POSITION ITS OPEN POSITION AGAINST THE ACTION OF SAID BIASING MEANS WHILE SAID SWITCH IS IN ITS CLOSED POSITION AND SAID MOTOR IS CONNECTED TO THE SOURCE OF ELECTRICAL ENERGY, SAID VALVE MEANS IN ITS OPEN POSITION FUNCTIONING TO ALLOW AIR TO FLOW SUCCESSIVELY THROUGH SAID SECOND PASSAGEWAY AND SAID COMMON PASSAGEWAY TO PROMOTE COOLING OF SAID MOTOR BY AIR FLOWING THERETHOUGH, WHEREBY SAID MOTOR WILL OPERATE AGAIN IN SAID NORMAL TEMPERATURE RANGE. 